Morrison will join other Pacific leaders in Tuvalu this week, where he will spell out how the money can be used, from 2020, by Pacific nations to invest in renewable energy and disaster resilience.
The money will be re-directed from existing aid programs and is not additional support for the region.
Morrison said the funding highlighted Australia's commitment to not just meeting our emissions reduction obligations at home but supporting its neighbours and friends.
The money is aimed at helping Pacific countries invest in renewable energy, as well as improving infrastructure in roads, hospitals and schools to withstand extreme weather events, the taxpayer-funded Australian Broadcasting Corporation reported.
Fiji's Prime Minister Frank Bainimarama spoke at the climate change 'Sautalaga' (open discussion) held this week, calling for stronger action from Australia, including phasing out coal-fired power generation.
"We face an existential threat that you don't face and challenges we expect your governments and people to more fully appreciate."
Bainimarama welcomed efforts by Australia and New Zealand to improve relations with Fiji and the region more broadly, but that did not stop him pushing for them to do more domestically to limit climate change.
"I certainly look forward to seeing for myself, the progress Australia has made in managing the challenges of transforming its energy sector and integrating renewable energy when I make my first official visit there next month."